The this.actor.height > this._maxHeight check is needed because animating the
dash out causes constant notify::height signals and so after each one the max
height would shrink to the actor height causing the icons to shrink until
eventually we get to 16px icons. This way, only increase maxHeight if the
actor can be drawn bigger than it is currently set.
https://bugzilla.gnome.org/show_bug.cgi?id=682050
9491f6bd23